Hamamatsu Photonics K.K. (浜松ホトニクス株式会社, Hamamatsu Hotonikusu Kabushiki-gaisha) is a Japanese manufacturer of optical sensors (including photomultiplier tubes), electric light sources, and other optical devices and their applied instruments for scientific, technical and medical use.The company was founded in 1953 by Heihachiro Horiuchi, a former student of Kenjiro Takayanagi, who is known as "the father of Japanese television".Hermann Simon, a leading German business author and thinker, mentioned Hamamatsu in his book titled Hidden Champions of the Twenty-First Century: The Success Strategies of Unknown World Market Leaders as an example of a "Hidden Champion".Hamamatsu CCD image sensors are used at the Subaru Telescope of the National Astronomical Observatory of Japan.Hamamatsu Photonics' photomultiplier tubes (PMTs) were used in the Super-Kamiokande neutrino detector facility at the University of Tokyo where 2015 Nobel Prize Laureate Takaaki Kajita conducted his research. In using products contributed by Hamamatsu Photonics, "Kajita was able to prove that neutrinos do in fact have mass -- a major shift in our fundamental understanding of how the universe works," said Tom Baer, chair of the Photonics Industry Neuroscience Group of the National Photonics Initiative. "This win is a tremendous accomplishment for Kajita and Hamamatsu Photonics."The sensors made by the company also helped confirm the existence of the Higgs boson in research that led to the 2013 Nobel Physics prize.
Sub-micrometer scale light patterns play a pivotal role in various fields, including biology, biophysics, and AMO physics. High-resolution, in situ observation of light profiles is essential for their design and application. However, current methods are constrained by limited spatial resolution and sensitivity. Additionally, no existing techniques allow for super-resolution imaging of the polarization profile, which is critical for precise control of atomic and molecular quantum states. Here, we present an atom camera technique for in situ imaging of light patterns with a single ultracold atom held by an optical tweezers as a probe. By scanning the atom's position in steps of sub-micrometers and detecting the energy shift on the spin states, we reconstruct high-resolution 2D images of the light field. Leveraging the extraordinarily long coherence time and polarization-sensitive transitions in the spin structure of the atom, we achieve highly sensitive imaging both for intensity and polarization. We demonstrate this technique by characterizing the polarization in a tightly-focused beam, observing its unique non-trivial profile for the first time. The spatial resolution is limited only by the uncertainty of the atom's position, which we suppress down to the level of quantum fluctuations ( 25 nm) in the tweezers' ground state. We thus obtain far better resolution than the optical diffraction limit, as well as than the previous ones obtained with a thermal atom fluctuating in the trap. This method enables the analysis and design of submicron-scale light patterns, providing a powerful tool for applications requiring precise light manipulation.
Aligning light spots into arbitrary shapes is a fundamental challenge in holography, leading to various applications across diverse fields in science and engineering. However, as the spot interval approaches the wavelength of light, interference effects among the spots become prominent, which complicates the generation of a distortion-free alignment. Herein, we introduce a hologram design method based on the optimization of a nonlinear cost function using a holographic phase pattern as the optimization parameter. We confirmed generation of a 5 x 5 multispot pattern, in which each spot is separated clearly by a distance of 0.952(1) mu m, on the focal plane of a high-numerical-aperture (0.75) objective by observing the near-infrared (wavelength: 820 nm) holographic output light from a spatial light modulator device. This result breaks through the spot spacing of a few micrometers that is a typical value achieved so far under similar experimental conditions. Furthermore, we propose redefinition of the Rayleigh diffraction limit by taking account of the separation of spot as well as the spot spacing. The proposed method is expected to advance laser fabrication, scanning laser microscopy, and cold atom physics, among other fields.
The growing demand for high-capacity quantum communication and large-scale quantum computing underscores the importance of networking quantum processing units via multiplexed photonic channels. A neutral atom array with multiplexed atom-photon entanglement is a promising platform for its realization. Here, we demonstrate a key multiplexed photonic interface guiding the photons from an atom array to a single-mode waveguide array fabricated on a glass-based photonic integrated circuit. Remarkable 10 channels out of the 32-channel waveguide array with 25 μm pitch couple to photons from 10 sites of the atom array with Rydberg gate-enabled separation. Based on the observed correlation between the atomic states and the polarization of the photon with a visibility of 0.87, we anticipate its applicability to a large-scale multiplexed atom-photon entanglement generation for networking quantum processing units.
Precise measurement of radiation has long played a vital role in a wide range of research and industrial fields, from fundamental physics beyond the Standard Model to medical imaging such as time-of-flight positron emission tomography. Developing radiation detectors that achieve high timing precision-on the order of a few tens of picoseconds-and energy measurement capabilities remains indispensable yet challenging. In this study, we developed two types of scintillator-integrated microchannel plate photomultiplier tubes (SCI-IMPs), one incorporating barium fluoride, and the other bismuth germanate, to enable simultaneous high-precision timing and energy measurements. To evaluate their performance over a wide energy range from keV- to GeV-scale, electron-positron annihilation gamma rays and cosmic ray muons were used. For energy measurements, both detectors achieved an energy resolution of approximately 35% at 511 keV. For timing measurements using 511 keV, coincidence time resolutions (CTRs) of approximately 50 ps full width at half maximum (FWHM) were obtained for both detectors. In contrast, for cosmic ray muon experiments where cosmic ray muon energy is typically on the order of GeV, CTRs were measured to be 25.1 and 16.8 ps FWHM for barium fluoride- and bismuth germanate-based detectors, respectively. The versatile scintillator-integration technique established in this study can broaden the applicability of the newly developed SCI-IMPs. In particular, these results demonstrate that the developed detectors push the boundaries of timing performance while retaining energy measurement and hold promise for future applications in fundamental physics experiments and medical imaging.
Molecules are emerging as new benchmark for metrology and fundamental physics research, driving the demand for spectroscopic techniques combining high sensitivity and resolution. Photoacoustic spectroscopy has proven to combine high sensitivity with appealing features like compactness, wavelength-independent and background-free detection. To date, photoacoustic sensing has mostly been focused on high-pressure applied trace-gas analysis, while accessing the low-pressure regime has been considered not compatible with efficient acoustic wave propagation. However, sensing gas samples at low pressure is the key to get access to high-resolution spectroscopy. Here, we demonstrate that sub-Doppler saturation spectroscopy can be performed on low-pressure trace gases in a cavity-enhanced photoacoustic sensor with mW-level mid-infrared radiation. Moreover, we show that the same setup can be operated at higher pressure, enabling trace-gas detection with 5 parts-per-billion sensitivity with a laser power as low as 35 microwatts. This allows to extend the unique advantages of the photoacoustic technique to metrology and fundamental physics and provides the mid-infrared with a cost-effective, flexible tool combining high sensitivity and resolution.
